Positive Crankcase Ventilation: Description and Operation

PCV System:

PURPOSE
Relieve crankcase pressure and prevent crankcase blowby vapors from entering the atmosphere.

LOCATION
PCV valve is in valve cover.

OPERATION
PCV valve is operated by intake manifold vacuum. At idle, only a small amount of blowby gas is drawn into the dynamic chamber. As engine speed increases, the quantity of blowby gas drawn in increases.